cas 3943-89-3, Ethyl 3,4-dihydroxybenzoate

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Synthesis, protolytic equilibria, and antimicrobial action of nifuroxazide analogs
The present paper reports on the synthesis of four hydrazones derived from 5-nitro-2-furfural, 5-nitro-2-thiophenal, isoniazid, 2,4- and 3,4-dihydroxy-N′-methylenebenzohydrazide. The acid-base dissociation constants of these compounds were determined in an aqueous solution. The protolytic equilibria-related ability of hydrazones to “sense” anions in dimethyl sulfoxide-containing water of different concentrations is studied using spectrophotometry, NMR spectroscopy, and quantum chemistry methods. The antimicrobial action of the hydrazones was tested and compared with that of the known drug nifuroxazide.
Gamov,Kiselev,Murekhina,Zavalishin,Aleksandriiskii,Kosterin, D.Yu.
(2021/07/16)

Synthesis and application of acrylic resin based on protocatechuic acid
The invention discloses synthesis and application of acrylic resin based on protocatechuic acid. According to the method, protocatechuic acid is used as a raw material, firstly, alcohol is used for esterification, and then the raw material and acryloyl chloride are synthesized into the protocatechuic acid-based acrylic resin monomer (M) through a one-pot method. And the acrylic resin based on protocatechuic acid is used for modifying polymethyl methacrylate (organic glass). The resin monomer is copolymerized with methyl methacrylate (MMA), the glass transition temperature (Tg) is increased along with the increase of the M content, and when the M content is 50%, the Tg of the copolymer is 159.6 DEG C (the heat resistance is improved by 51 DEG C). The Td5 of the copolymer is 358 DEG C (increased by 48 DEG C), and the residual carbon rate is 12.57%. In addition, the copolymerization product also shows the characteristic of absorbing short-wave blue light. The synthesis method provided by the invention is mild in reaction condition and relatively high in yield, and has a relatively great application prospect in the application field of optical electronics. The invention also widens the application range of biological resources.
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Paragraph 0049-0050; 0053-0054

(2021/06/26)

Modular Fragment Synthesis and Bioinformatic Analysis Propose a Revised Vancoresmycin Stereoconfiguration
Elaborate fragments of the proposed stereostructure of the complex polyketide antibiotic vancoresmycin have been synthesized in a stereoselective fashion based on a modular and convergent approach. Significant nuclear magnetic resonance differences in one of these subunits compared with the natural product question the proposed stereoconfiguration. Consequently, an extensive bioinformatics analysis of the biosynthetic gene cluster was carried out, leading to a revised stereoconfigurational proposal for this highly potent antibiotic.
Adamek, Martina,Essig, Sebastian,Kurz, Michael,Menche, Dirk,Sch?nenbroicher, Max,Seul, Maximilian,Spindler, Stefanie,Wingen, Lukas M.,Ziemert, Nadine
supporting information
p. 1175 - 1180
(2021/01/13)

Anchimerically Assisted Selective Cleavage of Acid-Labile Aryl Alkyl Ethers by Aluminum Triiodide and N, N-Dimethylformamide Dimethyl Acetal
Aluminum triiodide is harnessed by N,N-dimethylformamide dimethyl acetal (DMF-DMA) for the selective cleavage of ethers via neighboring group participation. Various acid-labile functional groups, including carboxylate, allyl, tert-butyldimethylsilyl (TBS), and tert-butoxycarbonyl (Boc), suffer the conditions intact. The method offers an efficient approach to cleaving catechol monoalkyl ethers and to uncovering phenols from acetal-type protecting groups such as methoxymethyl (MOM), methoxyethoxymethyl (MEM), and tetrahydropyranyl (THP) chemoselectively.
Sang, Dayong,Yue, Huaxin,Zhao, Zhengdong,Yang, Pengtao,Tian, Juan
p. 6429 - 6440
(2020/07/14)

Selective ether bond breaking method of aryl alkyl ether
The invention discloses a selective aryl alkyl ether cracking method, which comprises that aryl alkyl ether, aluminum iodide and an additive are subjected to a selective ether bond cleavage reaction in an organic solvent at a temperature of -20 DEG C to a reflux temperature to generate phenol and derivatives thereof. The method is mild in condition and simple and convenient to operate, is suitablefor cracking aryl alkyl ether containing o-hydroxyl and o-carbonyl and acetal ether, and can also be used for removing tertiary carbon hydroxyl protecting groups with higher steric hindrance, such astriphenylmethyl, tertiary butyl and the like.
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Paragraph 0070-0080

(2020/09/16)

Mechanistic studies of hydrogen-peroxide-mediated anthocyanin oxidation
The oxidation of cyanidin-3-O-glucoside by hydrogen peroxide was investigated in a range of solvents. The reaction products had chemical structures identical to those formed by the reaction of this compound with the alkylperoxyl radical 2,2?-azobis(2,4-dimethyl)valeronitrile. A plausible oxidation mechanism was proposed based on the obtained reaction products, and this mechanism was confirmed by HPLC–MS experiments using 18O-labeled reagents. Further, the reaction conditions were found to influence both the reaction rate and the products formed during the transformation, which validated the proposed mechanism.
Satake, Ryuya,Yanase, Emiko
p. 6187 - 6191
(2018/09/17)

Design of antibacterial agents: Alkyl dihydroxybenzoates against xanthomonas citri subsp. citri
Xanthomonas citri subsp. citri (Xcc) causes citrus canker, affecting sweet orange-producing areas around the world. The current chemical treatment available for this disease is based on cupric compounds. For this reason, the objective of this study was to design antibacterial agents. In order to do this, we analyzed the anti-Xcc activity of 36 alkyl dihydroxybenzoates and we found 14 active compounds. Among them, three esters with the lowest minimum inhibitory concentration values were selected; compounds 4 (52 μM), 16 (80 μM) and 28 (88 μM). Our study demonstrated that alkyl dihydroxybenzoates cause a delay in the exponential phase. The permeability capacity of alkyl dihydroxybenzoates in a quarter of MIC was compared to nisin (positive control). Compound 28 was the most effective (93.8), compared to compound 16 (41.3) and compound 4 (13.9) by percentage values. Finally, all three compounds showed inhibition of FtsZ GTPase activity, and promoted changes in protofilaments, leading to depolymerization, which prevents bacterial cell division. In conclusion, heptyl dihydroxybenzoates (compounds 4, 16 and 28) are promising anti-Xcc agents which may serve as an alternative for the control of citrus canker.
Nazaré, Ana Carolina,Polaquini, Carlos Roberto,Anselmo, Daiane Bertholin,Regasini, Luis Octavio,Cavalca, Lúcia Bonci,Ferreira, Henrique,Zielinska, Aleksandra,Scheffers, Dirk-Jan,Saiki, Marilia de Freitas Calmon,Monteiro, Diego Alves,Rahal, Paula,Gomes, Eleni
(2018/11/21)

Ethyl acetate as a co-solvent and sacrificial ester in the aluminum triiodide promoted chemoselective demethylation of methyl vanillate
A synthetic approach towards methyl protocatechuate via chemoselective ether cleavage of methyl vanillate without affecting the carboxylate group is disclosed utilizing a ternary reagent system consisting of aluminum triiodide, 1,3-diisopropylcarbodiimide and ethyl acetate. Ethyl acetate serves as a co-solvent and sacrificial ester. Methyl isovanillate, ethyl vanillate and methyl feruate were analogously demethylated to give methyl protocatechuate, ethyl protocatechuate and methyl caffeate, respectively, in fair to excellent yields.
Tian, Juan,Yi, Cuicui,Fang, Huasheng,Sang, Dayong,He, Zhoujun,Wang, Jiahui,Gan, Yongjiang,An, Qing
supporting information
p. 3522 - 3524
(2017/10/06)

Solar lab and pilot scale photo-oxidation of ethylparaben using H2O2 and TiO2 in aqueous solutions
Ethylparaben (Eth-PB) is one of the most used parabens for preservation of many personal care products and food. However, a number of scientific studies have indicated that this compound could interfere with the endocrine or hormonal system of different living beings, which along with data about its presence in different water bodies generates the necessity of seeking alternatives to minimize the potential negative effect of this situation. In this way, removal of Eth-PB using heterogeneous photocatalysis with TiO2, hydrogen peroxide and light radiation (solar spectrum: wavelength >290 nm) was assessed, considering the individual effects of different operational parameters like the catalyst and H2O2 dosages, the pH and the pollutant initial concentration. According to this, conditions that, under the experimental range, promote a higher paraben elimination were established. Tests were carried out at lab-scale using a photo-simulator equipped with a Xenon lamp, and at pilot scale (volume treated ～100 L) using a compound parabolic collector and direct solar light radiation. In both cases, more than a 80% of substrate elimination was reached in less than 6 h of reaction, demonstrating the effectiveness of the photocatalytic system to remove this kind of compounds. Additionally, a significant reduction of the total organic carbon present in the solutions, and an increment of the biodegradability of the samples were appreciated. Finally, some of the by-products generated during the contaminant removal were identified.
Zú?iga-Benítez, Henry,Pe?uela, Gustavo A.
p. 62 - 70
(2017/02/05)

A method for preparing environmental protection of erlotinib hydrochloride
The invention discloses an environment-friendly method for preparing high-yield erlotinib hydrochloride. The method comprises the following steps: directly performing cyclic condensation by taking 2-amino-4,5-di(2-methoxy ethyoxyl) ethyl benzoate hydrochloride as a key intermediate, reacting with aminophenylacetylene to generate erlotinib hydrochloride after performing chlorination, and refining to obtain the high-purity erlotinib hydrochloride. The process route provided by the invention is mild in reaction condition and high in yield; the first-class reagent and other reagents harmful to the environment and the operators are not used, the byproduct is few, the aftertreatment is simple and the commercial process can be easily processed.
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Paragraph 0066-0068

(2017/09/26)

Oxadiazole compound and application thereof to preparation of medicament for preventing and/or treating type 2 diabetes
The invention relates to a total chemical synthesis method for novel oxadiazole PTP1B (protein tyrosine phosphatase 1B) and application of the novel oxadiazole PTP1B to a medicament for treating type 2 diabetes. The structural formula of the oxadiazole compound is shown in the description. The activity of PTP1B is inhibited, and the sensitivity of an insulin receptor is enhanced, so that the compound has good treatment effects on insulin resistance type 2 diabetes.
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Paragraph 0020-0021

(2017/07/07)

2,6-Difluorobenzamide Inhibitors of Bacterial Cell Division Protein FtsZ: Design, Synthesis, and Structure–Activity Relationships
A wide variety of drug-resistant microorganisms are continuously emerging, restricting the therapeutic options for common bacterial infections. Antimicrobial agents that were originally potent are now no longer helpful, due to their weak or null activity toward these antibiotic-resistant bacteria. In addition, none of the recently approved antibiotics affect innovative targets, resulting in a need for novel drugs with innovative antibacterial mechanisms of action. The essential cell division protein filamentous temperature-sensitive Z (FtsZ) has emerged as a possible target, thanks to its ubiquitous expression and its homology to eukaryotic β-tubulin. In the latest years, several compounds were shown to interact with this prokaryotic protein and selectively inhibit bacterial cell division. Recently, our research group developed interesting derivatives displaying good antibacterial activities against methicillin-resistant Staphylococcus aureus, as well as vancomycin-resistant Enterococcus faecalis and Mycobacterium tuberculosis. The aim of the present study was to summarize the structure–activity relationships of differently substituted heterocycles, linked by a methylenoxy bridge to the 2,6-difluorobenzamide, and to validate FtsZ as the real target of this class of antimicrobials.
Straniero, Valentina,Zanotto, Carlo,Straniero, Letizia,Casiraghi, Andrea,Duga, Stefano,Radaelli, Antonia,De Giuli Morghen, Carlo,Valoti, Ermanno
p. 1303 - 1318
(2017/09/01)

Design, synthesis and biological evaluation of uncharged catechol derivatives as selective inhibitors of PTP1B
Protein tyrosine phosphatases 1B (PTP1B) is a promising and validated therapeutic target to effectively treat T2DM and obesity. However, the development of charged PTP1B inhibitors was restricted due to their low cell permeability and poor bioavailability. Based on active natural products, two series of uncharged catechol derivatives were identified as PTP1B inhibitors by targeting a secondary aryl phosphate-binding site as well as the catalytic site. The most potent inhibitor 22 showed an IC50 of 0.487?μM against PTP1B and strong selectivity (27-fold) over TCPTP. Kinetic studies were also performed that 22 act as a competitive PTP1B inhibitor. The treatment of C2C12 myotubes with 22 markedly increased the phosphorylation levels of IRβ, Akt and IRS1 phosphorylation. The similarity of its action profiling with that produced by insulin suggested its potential as a new non-insulin-dependent drug candidate.
Li, Xiang-Qian,Xu, Qi,Luo, Jiao,Wang, Li-Jun,Jiang, Bo,Zhang, Ren-Shuai,Shi, Da-Yong
p. 348 - 359
(2017/05/17)

Conversion of Simple Cyclohexanones into Catechols
A novel I2-catalyzed direct conversion of cyclohexanones to substituted catechols under mild and simple conditions has been described. This novel transformation is remarkable with the multiple oxygenation and dehydrogenative aromatization processes enabled just by using DMSO as the solvent, oxidant, and oxygen source. This metal-free and simple system demonstrates a versatile protocol for the synthesis of highly valuable substituted catechols and therefore streamlines the synthesis and modification of biologically important molecules for drug discovery.
Liang, Yu-Feng,Li, Xinyao,Wang, Xiaoyang,Zou, Miancheng,Tang, Conghui,Liang, Yujie,Song, Song,Jiao, Ning
supporting information
p. 12271 - 12277
(2016/09/28)

Oxidative esterification via photocatalytic C-H activation
Direct oxidative esterification of alcohol via photocatalytic C-H activation has been developed using VO@g-C3N4 catalyst; an expeditious esterification of alcohols occurs under neutral conditions using visible light as the source of energy.
Verma, Sanny,Baig, R. B. Nasir,Han, Changseok,Nadagouda, Mallikarjuna N.,Varma, Rajender S.
p. 251 - 254
(2015/12/31)

Synthesis of Catecholate Ligands with Phosphonate Anchoring Groups
New catecholate ligands containing protected phosphonate anchoring groups in the 4-position of the catecholate ring were synthesized. The catechol 4-diethoxyphosphorylbenzene-1,2-diol, (Etphoscat)H2, was prepared in three steps from pyrocatechol; whereas, the catechol 4-(diethoxyphosphorylmethyl)benzene-1,2-diol, (EtBnphoscat)H2, containing a methylene spacer between the catecholate ring and phosphonate anchor, was prepared from protocatechuic acid in six linear steps. Both catechol derivatives were further elaborated to their trimethylsilyl-protected counterparts to facilitate their binding to nanocrystalline metal oxides. Electronic spectroscopy and cyclic voltammetry were used to probe the electronic properties of the phosphonate-functionalized catecholates in charge-transfer complexes of the general formula (catecholate)Pd(pdi) (pdi = N,N′-bis(mesityl)phenanthrene-9,10-diimine). These studies show that attachment of the phosphonate anchor directly to the 4-position of the (Etphoscat)2- ligand significantly perturbs the donor ability of the catecholate ligand; however, incorporation of a single methylene spacer group in (EtBnphoscat)2- helps to isolate catecholate from the electron-withdrawing phosphonate group.
Seraya, Elaine,Luan, Zhongyue,Law, Matt,Heyduk, Alan F.
p. 7571 - 7578
(2015/08/11)

Novel oxidation products of cyanidin 3-O-glucoside with 2,2′-azobis-(2,4-dimethyl)valeronitrile and evaluation of anthocyanin content and its oxidation in black rice
The radical oxidation mechanism of anthocyanin derivatives was investigated by the reaction of cyanidin 3-O-glucoside in the presence of radical initiator 2,2′-azobis-(2,4-dimethyl)valeronitrile (AMVN) in EtOH and aqueous CH 3CN. Six different oxidation products were isolated, depending on the solvent employed. These products were identified using NMR spectroscopy and multistep derivatisation reactions. Of the products obtained, two novel oxidised anthocyanin derivatives were isolated from black rice under prolonged storage. A radical reaction mechanism is proposed on the basis of these reaction products. Quantification of oxidised anthocyanins in black rice is demonstrated as a method to verify freshness of the rice.
Kamiya, Haruna,Yanase, Emiko,Nakatsuka, Shin-Ichi
p. 221 - 226
(2014/03/21)

Design, synthesis and biological evaluation of small molecular polyphenols as entry inhibitors against H5N1
To find novel compounds against H5N1, three series of known or novel small molecular polyphenols were synthesized and tested in vitro for anti-H5N1 activity. In addition, the preliminary structure-antiviral activity relationships were elaborated. The results showed that some small molecular polyphenols had better anti-H5N1 activity, and could serve as novel virus entry inhibitors against H 5N1, likely targeting to HA2 protein. Noticeably, compound 4a showed the strongest activity against H5N1 among these compounds, and the molecular modeling analysis also suggested that this compound might target to HA2 protein. Therefore, compound 4a is well qualified to serve as a lead compound or scaffold for the further development of H 5N1 entry inhibitor.
Yang, Jian,Yang, Jing Xiang,Zhang, Fang,Chen, Gang,Pan, Wei,Yu, Rui,Wu, Shuwen,Tien, Po
p. 2680 - 2684
(2014/06/09)

An efficient strategy for protecting dihydroxyl groups of catechols
A novel strategy for protecting dihydroxyl groups of catechols has been developed. Base-mediated cyclizations of catechols with 1,3-dibromopropane provided the corresponding benzo[b]1,4-dioxepans, and herefrom the protecting group was easily cleaved by aluminum chloride. The preparation of the antibacterial and antifungal agent 4-(2-aminothiazol-4-yl)benzene-1,2-diol from catechol reliably verified its availability amenable to various harsh reaction conditions. Georg Thieme Verlag Stuttgart - New York.
Huang, Wei-Bin,Guo, Ying,Jiang, Jian-An,Pan, Xian-Dao,Liao, Dao-Hua,Ji, Ya-Fei
supporting information
p. 741 - 746
(2013/05/09)

Mono-/dihydroxybenzoic acid esters and phenol pyridinium derivatives as inhibitors of the mammalian carbonic anhydrase isoforms I, II, VII, IX, XII and XIV
Using hydroxy-/dihydroxybenzoic acids as leads, a series of methyl, ethyl and iso-propyl esters of 4-hydroxy-benzoic acid, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-dihydroxybenzoic acids and of coumaric acid, were obtained and investigated for the inhibition of six mammalian carbonic anhydrase (CA, EC 4.2.1.1) isoforms, that is, the cytosolic CA I, II and VII, and the transmembrane CA IX, XII and XIV, many of which are established drug targets. Other compounds incorporating phenol/catechol moieties were obtained from dopamine by reaction with fluorescein isothiocyanate or with 2,4,6-trisubstituted pyrylium salts. Some aminophenols were also derivatized in a similar manner, by using pyrylium salts. Many of these compounds showed increased inhibitory action compared to the lead compounds from which they were obtained, with efficacy in the submicromolar range against most investigated CA isoforms. As phenols are a class of less investigated CA inhibitors (CAIs) compared to the sulfonamides, and their mechanism of inhibition is less well understood, compounds of the type designed here may be helpful in gaining more insights into these phenomena.
Carta, Fabrizio,Vullo, Daniela,Maresca, Alfonso,Scozzafava, Andrea,Supuran, Claudiu T.
supporting information
p. 1564 - 1569
(2013/04/10)

Flavone-based novel antidiabetic and antidyslipidemic agents
The hybrid congeners 62-90 of 6- and 7-hydroxyflavones with aminopropanol have been synthesized and evaluated for their antidiabetic activity in sucrose-challenged low-dosed streptozotocin (STZ)-induced diabetic rats and db/db mice. The optical enantiomers 70a, 70b, 90a, and 90b of two congeners 70 and 90 exhibiting consistent antidiabetic and antidyslipidemic activities were also prepared, and their antidiabetic activity results indicate its association mainly with S isomers. These compounds also lower cholesterol and TG profiles while improving high-density lipoprotein cholesterol to CHOL ratio in db/db mice. The bioavailability of compound 70 and its isomer varies between 27 and 29% whereas that of the more polar compound 90a is poor as determined in rat by oral and intraperitoneal administrations. Published 2012 by the American Chemical Society.
Verma, Alok K.,Singh, Himanshu,Satyanarayana, Mavurapu,Srivastava, Swayam P.,Tiwari, Priti,Singh, Amar B.,Dwivedi, Anil K.,Singh, Shio K.,Srivastava, Mukesh,Nath, Chandishwar,Raghubir, Ram,Srivastava, Arvind K.,Pratap, Ram
supporting information; experimental part
p. 4551 - 4567
(2012/07/30)

Alkyl hydroxybenzoic acid derivatives that inhibit HIV-1 protease dimerization
The therapeutic potential of gallic acid and its derivatives as anti-cancer, antimicrobial and antiviral agents is well known. We have examined the mechanism by which natural gallic acid and newly synthesized gallic acid alkyl esters and related protocatechuic acid alkyl esters inhibit HIV-1 protease to compare the influence of the aromatic ring substitutions on inhibition. We used Zhang-Poorman's kinetic analysis and fluorescent probe binding to demonstrate that several gallic and protecatechuic acid alkyl esters inhibited HIV-1 protease by preventing the dimerization of this obligate homodimeric aspartic protease rather than targeting the active site. The tri-hydroxy substituted benzoic moiety in gallates was more favorable than the di-substituted one in protocatechuates. In both series, the type of inhibition, its mechanism and the inhibitory efficiency dramatically depended on the length of the alkyl chain: no inhibition with alkyl chains less than 8 carbon atoms long. Molecular dynamics simulations corroborated the kinetic data and propose that gallic esters are intercalated between the two N- and C-monomer ends. They complete the β-sheet and disrupt the dimeric enzyme. The best gallic ester (14 carbon atoms, Kid of 320 nM) also inhibited the multi-mutated protease MDR-HM. These results will aid the rational design of future generations of non-peptide inhibitors of HIV-1 protease dimerization that inhibit multi-mutated proteases. Finally, our work suggests the wide use of gallic and protocatechuic alkyl esters to dissociate intermolecular β-sheets involved in protein-protein interactions.
Flausino Jr., O. A.,Dufau, L.,Reboud-Ravaux, M.,Regasini, L. O.,Petronio, M. S.,Silva, D. H. S.,Bolzani, V. S.,Rose, T.
p. 4534 - 4540,7
(2012/12/12)

Synthesis of catechols from phenols via Pd-catalyzed silanol-directed C-H oxygenation
A silanol-directed, Pd-catalyzed C-H oxygenation of phenols into catechols is presented. This method is highly site selective and general, as it allows for oxygenation of not only electron-neutral but also electron-poor phenols. This method operates via a silanol-directed acetoxylation, followed by a subsequent acid-catalyzed cyclization reaction into a cyclic silicon-protected catechol. A routine desilylation of the silacyle with TBAF uncovers the catechol product.
Huang, Chunhui,Ghavtadze, Nugzar,Chattopadhyay, Buddhadeb,Gevorgyan, Vladimir
supporting information; experimental part
p. 17630 - 17633
(2011/12/16)

Syntheses and characterization of nimesulide derivatives for dual enzyme inhibitors of both cyclooxygenase-1/2 and 5-lipoxygenase
Cyclooxygenase-1/2 (COX-1/2) and 5-lipoxygenase (5-LOX) are enzymes in two different pathways in the inflammatory process. In the present study, a variety of new nimesulide derivatives were synthesized through incorporation of a 5-LOX pharmacophore into nimesulide followed with some structural modifications, which were then characterized for dual enzyme inhibitors for these two types of enzymes. Their structure-activity relationships (SARs) were studied, and compound 20f was found to be an excellent dual enzyme inhibitor. Its binding conformation and interaction mode were studied with molecular docking experiments. Compound 20f could become a lead compound for further development for potential anti-inflammatory drugs.
Li, Yue,Chen, Shu-Han,Ou, Tian-Miao,Tan, Jia-Heng,Li, Ding,Gu, Lian-Quan,Huang, Zhi-Shu
scheme or table
p. 2074 - 2083
(2011/05/05)

Synthesis and radical polymerisation of methacrylic monomers with crown ethers or their dipodal counterparts in the pendant structure
The synthesis and radical polymerisation of methacrylic monomers with benzo-12-crown-4, benzo-15-crown-5, benzo-18-crown-6, and their dipodal counterparts in the ester residue is described. The radical polymerisation of the monomers in solution was carried out at different temperatures, and the polymerisation kinetics curves were obtained by direct measurement of the instantaneous monomer concentrations by nuclear magnetic resonance spectroscopy (NMR). Thus, the polymerisation rate parameter (2fkp/〈k t〉1/2), along with the polymer stereoregularity, were obtained in terms of the molar fractions of meso and racemo diads and of syndiotactic, isotactic and heterotactic triads. The interaction of the polymers with cations was studied using polymer networks as solid phases in the solid-liquid extraction of lanthanide cations from both organic and aqueous media.
Rey, Jimena,Garcia, Felix Clemente,Garcia, Jose Miguel
scheme or table
p. 948 - 957
(2012/03/27)

Structure-property-activity relationship of phenolic acids and derivatives. Protocatechuic acid alkyl esters
The esterification of hydrophilic phenolic antioxidants is an efficient approach to enhance their solubility in apolar media. Herein, structurea property studies on the antiradical activity of a series of protocatechuic acid alkyl esters have been accomplished. The increase of the lipophilicity was shown to significantly improve the antioxidant activity of protocatechuic esters. Their efficiency as radical scavengers was evaluated using distinctive analytical methods, namely, 2,2-diphenyl-1-picrylhydrazyl (DPPH) UV/visible method, electrochemistry, and differential scanning calorimetry. All the new alkyl protocatechuate antioxidants studied possessed better radical-scavenging capacity than the natural antioxidant protocatechuic acid. This work has shown that the alkyl ester side chain markedly influences the lipophilicity of this type of phenolic system without disturbing the core of the molecule responsible for antioxidant activity. The data on the antioxidant activity obtained using the different analytical methods correlated well with each other and have revealed the interesting antioxidant potential of alkyl esters of protocatechuic acid.
Reis, Bruno,Martins, Marta,Barreto, Barbara,Milhazes, Nuno,Garrido, E. Manuela,Silva, Paulo,Garrido, Jorge,Borges, Fernanda
experimental part
p. 6986 - 6993
(2011/08/06)

Dual polyrotaxane: One-pot synthesis of topological polymer by using metathesis reaction
The topological polyrotaxane was built from an ammonium salt as an axle component bearing one olefin and one bulky unit at the end of chain and the derivative of dibenzo-24-crown-8 (DB24C8) as a wheel component having one terminal olefin. In this system, two kinds of reactions work at the same time as a driving force of the polymer construction. One is the inclusion reaction between the ammonium salt part of axle and the wheel, another is metathesis reaction between olefins of the axle and olefins of the wheel. Copyright
Yamabuki, Kazuhiro,Isobe, Yukio,Onimura, Kenjiro,Oishi, Tsutomu
p. 1196 - 1197
(2008/03/13)

OXY SUBSTITUTED FLAVONES AS ANTIHYPERGLYCEMIC AND ANTIDYSLIPIDEMIC AGENTS
The present invention provides novel substituted flavone derivatives which exhibit anti- hyperglycemic and antidyslipedemic activity. The invention also provides a method for controlling type ii diabetes and associated hyperlipidemic conditions in a mammal by administering compound of the present invention and compositions containing these derivatives.
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Page/Page column 14

(2010/11/08)

New selective O-debenzylation of phenol with Mg/MeOH
Carboxylate-benzyl and nitro-benzyl groups used in phenols protection were selectively debenzylated with 3-25 equiv of Mg in methanol at room temperature. Good yields of the desired phenols were obtained within 3-10 h from a wide variety of O-(carboxylate-benzyl)- or O-(nitro-benzyl)-phenols. Selective O-debenzylation was possible in the presence of O-(carboxylate-benzyl)- or O-(nitro-benzyl)-phenols with Mg/MeOH.
Huang, Wei,Zhang, Xu,Liu, Hong,Shen, Jianhua,Jiang, Hualiang
p. 5965 - 5967
(2007/10/03)

2-hydroxypropylamine heteroaryl ester derivatives
The present invention relates to compounds of the general formula STR1 wherein Ar represents a substituted or unsubstituted heterocyclic group; W represents alkylene of from 1 to about 10 carbon atoms; and B represents --NR2 COR1, --NR2 CONR1 R3, --NR2 SO2 R1, NR2 SO2 NR1 R3, or --NR2 COOR1, wherein R1, R2 and R3 may be alike or different and may be hydrogen, alkyl, alkoxyalkyl cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl, except that R1 is not hydrogen when B is --NR2 SO2 R1 or --NR2 COOR1, or R1 and R3 may together with N form a 5 to 7 membered heterocyclic group and the pharmaceutically acceptable salts thereof. The compounds exhibit beta-adrenergic blocking activity and are also useful in the treatment of glaucoma.
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(2008/06/13)

AROMATIC AND ESTERS OF HYDROXYPROPYLAMINES
Novel compounds of the general formula STR1 wherein Ar represents a substituted or unsubstituted aromatic or heterocyclic group; W represents alkylene of from 1 to about 10 carbon atoms; and B represents--NR 2 COR 1,--NR 2 CONR 1 R 3,--NR 2 SO 2 R. sub.1,--NR 2 SO 2 NR 1 R 3, or--NR 2 COOR 1 wherein R. sub.1, R 2 and R 3 may be the same or different and may be hydrogen, alkyl, alkoxyalkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl, except that R 1 is not hydrogen when B is--NR 2 SO 2 R 1 or--NR 2 COOR 1, or R 1 and R 3 may together with N form a 5 to 7 momoered heterocyclic group; and the pharmaceutically acceptable salts thereof. These compounds exhibit β-adrenergic blocking activity and are also useful in the treatment of glaucoma.
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(2008/06/13)

Method for treating glaucoma by the topical administration of selectively metabolized beta-blocking agents
A method for the treatment of glaucoma or lowering intraocular pressure in a mammal, involving topically administering to the eye of such mammal a selectively metabolized beta-blocking compound of the formula STR1 wherein R may be lower alkyl, lower hydroxyalkyl, lower alkynyl, aralkyl, or an ester-containing group and Ar may be substituted or unsubstituted aromatic; or a pharmaceutically acceptable salt thereof. Because of a relatively long duration of action of such compounds in ocular fluids and a relatively short duration of action in the systemic circulation, such compounds are useful for the treatment of excessive intraocular pressure without substantial systemic effects.
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(2008/06/13)